// None of the originally given control deps are necessary.
  tf_executor::FetchOp fetch_op = graph_op.GetFetch();
  int num_control_fetches =
      fetch_op.getNumOperands() - graph_op.getNumResults();
  if (num_control_fetches > 0) {
    fetch_op.getFetchesMutable().erase(graph_op.getNumResults(),
                                       num_control_fetches);
  }
}

  GraphOp graph_op = GetGraphOpFromFuncOp(init_func_op);
  if (!graph_op) return success();  // Consider empty FuncOp valid.

  FetchOp fetch_op = graph_op.GetFetch();
  for (const Value fetch : fetch_op.getFetches()) {
    if (!mlir::isa<tf_executor::ControlType>(fetch.getType())) {
      fetch_op.emitError(absl::StrFormat(
          "Validation failed for the initializer function: %s. "

// op, otherwise, the pass will signal failure.

func.func @graph_multiple_islands() {
  // expected-error@+1 {{expected graph op to contain only a single island_op and a single fetch_op}}
  tf_executor.graph {
    tf_executor.island {
      "tf.NoOp"() : () -> ()
      tf_executor.yield
    }
    tf_executor.island {
      "tf.NoOp"() : () -> ()
      tf_executor.yield
    }

    if (!HasSingleOpInBlock<IslandOp>(&block)) return failure();

    FetchOp fetch_op = op.GetFetch();
    auto island_op = llvm::cast<IslandOp>(block.front());
    YieldOp yield_op = island_op.GetYield();

    // Map graph results to inner ops results of single island.
    llvm::SmallVector<Value, 8> new_rets;
    for (Value operand : fetch_op.getFetches()) {
      // Control results should not be propagated out.

// `FetchOp` will be used without modified. Returns the fetch operands from the
// `scr_graph_op`.
Value CloneGraphOps(GraphOp src_graph_op, GraphOp dst_graph_op,
                    IRMapping& mapper) {
  Block& main_body = dst_graph_op.GetBody();

  // Take the reference of the main graph's FetchOp to later move to the end.
  FetchOp main_fetch_op = dst_graph_op.GetFetch();

  // parentheses is needed for successful compilation.
  assert((isa<IslandOp, FetchOp>(op)));
  if (auto island = dyn_cast<IslandOp>(op)) {
    num_control_inputs_removed += island.getControlInputs().size();
    island.getControlInputsMutable().clear();
  } else if (auto fetch = dyn_cast<FetchOp>(op)) {
    GraphOp graph = fetch->getParentOfType<GraphOp>();

# Verify for functions with control return values, the island with a consumed
# data output and a consumed control has both its outputs added to the GraphOps
# FetchOp.

# Match the island containing the "tf.Neg", capture the output
# CHECK:          %[[ISLAND:[a-z_0-9]*]], %[[ISLAND_control:[a-z_0-9]*]] = tf_executor.island wraps "tf.Neg"

# Verify for functions with control return values, the island with only a
# consumed control return value has its control output added to the GraphOps
# FetchOp.

# Match the island containing the "tf.Neg", capture the output
# CHECK:          %[[ISLAND_0:[a-z_0-9]*]], %[[ISLAND_0_control:[a-z_0-9]*]] = tf_executor.island wraps "tf.Neg"

  args_[arg] = node;
  return absl::OkStatus();
}

// Creates return nodes per operand of a FetchOp. If names is supplied, those
// names will be used per node in order instead of generating a unique name.
Status Exporter::AddFetchNode(FuncOp function, mlir::tf_executor::FetchOp fetch,
                              llvm::ArrayRef<llvm::StringRef> names) {
  auto& return_nodes = returns_[fetch];

  args_[arg] = node;
  return absl::OkStatus();
}

// Creates return nodes per operand of a FetchOp. If names is supplied, those
// names will be used per node in order instead of generating a unique name.
Status Exporter::AddFetchNode(FuncOp function, mlir::tf_executor::FetchOp fetch,
                              llvm::ArrayRef<llvm::StringRef> names) {
  auto& return_nodes = returns_[fetch];